how to have self confidence in public

i have anxiety combined with paranoia and outside i can feel very on edge, panicked and unnerved and not self assured or self confident, i doubt myself at times too.....i rush around, sweat a lot, my hands shake with nerves, i look around for any signs of danger...and i'm dying with nerves some days..

all i want is to be self confident and relaxed in public places....anyone know how i can?